Transfer for a vehicle

Abstract

A transfer for a vehicle, the transfer includes an input rotating member, a first output rotating member, a second output rotating member, a high-low switching mechanism, a clutch, a motor, a screw mechanism and a transmitting mechanism. The first output rotating member outputs power to first left and right wheels. The second output rotating member outputs power to second left and right wheels. The high-low switching mechanism changes a rate of rotation from the input rotating member and transmits the rotation to the first output rotating member. The clutch adjusts a transfer torque. The transfer torque is transmitted from the first output rotating member to the second output rotating member. The screw mechanism converts rotational motion of the motor to linear motion. The transmitting mechanism transmits linear motion force of the screw mechanism to both the high-low switching mechanism and the clutch.

What is claimed is: 
     
       1. A transfer for a vehicle, the vehicle including first left and right wheels and second left and right wheels, the transfer comprising:
 an input rotating member; 
 a first output rotating member configured to output power to the first left and right wheels; 
 a second output rotating member configured to output power to the second left and right wheels; 
 a high-low switching mechanism configured to change a rate of rotation from the input rotating member and transmit the rotation to the first output rotating member; 
 a clutch configured to adjust a transfer torque, the transfer torque being transmitted from the first output rotating member to the second output rotating member; 
 a motor; 
 a screw mechanism configured to convert rotational motion of the motor to linear motion; and 
 a transmitting mechanism configured to transmit linear motion force of the screw mechanism to both the high-low switching mechanism and the clutch, wherein 
 the screw mechanism includes a rotating motion member and a linear motion member, the rotating motion member being directly or indirectly connected to the motor, the linear motion member being connected to the rotating motion member in a manner movable in a direction parallel to an axial center of the rotating motion member in response to rotation of the rotating motion member, 
 the high-low switching mechanism includes a high-low sleeve, high side gear teeth that output rotation, and low side gear teeth that output rotation at a slower speed than the high side gear teeth, the high-low sleeve is splined engaged with the first output rotating member, and the high-low sleeve is configured to move in a direction parallel to the axial center of the first output rotating member such that the high-low sleeve meshes with the high side gear teeth and the low side gear teeth, respectively, and 
 the transmitting mechanism includes a pressing member, a fork shaft and a fork, the pressing member is connected to the linear motion member, the pressing member is configured to press on the clutch, the fork shaft is provided around another axial center that is parallel to the axial center of the rotating motion member, and the fork shaft is connected to the linear motion member, and the fork is fixed on the fork shaft and the fork is connected to the high-low sleeve. 
 
     
     
       2. The transfer according to  claim 1 , further comprising:
 a dog clutch configured to connect the first output rotating member and the second output rotating member together in an integrated manner, 
 wherein the transmitting mechanism is configured to transmit the linear motion force of the screw mechanism to the dog clutch. 
 
     
     
       3. The transfer according to  claim 1 , further comprising:
 a dog clutch including locking teeth and a locking sleeve, the locking teeth being provided on the second output rotating member, and the locking sleeve being spline engaged with the first output rotating member, the locking sleeve being configured to move in the direction parallel to the axial center of the first output rotating member such that the locking sleeve meshes with the locking teeth, 
 wherein the transmitting mechanism is configured to transmit the linear motion force of the screw mechanism to the locking sleeve via the high-low sleeve. 
 
     
     
       4. The transfer according to  claim 3 , wherein
 the high-low sleeve is provided between the second output rotating member and a support bearing of the input rotating member; 
 the locking sleeve is provided separate from and adjacent to the high-low sleeve, between the high-low switching mechanism and the second output rotating member; and 
 the transmitting mechanism includes a first spring and a second spring, the first spring urging the high-low sleeve and the locking sleeve toward sides away from each other, the second spring urging the locking sleeve toward a side away from the locking teeth. 
 
     
     
       5. The transfer according to  claim 4 , wherein
 the high-low sleeve is configured to mesh with the high side gear teeth on the side away from the locking sleeve, and the high-low sleeve is configured to mesh with the low side gear teeth on the side near the locking sleeve; 
 the locking sleeve is configured to mesh with the locking teeth when the fork shaft is in a position that places the high-low sleeve in mesh with the low side gear teeth; 
 the clutch is arranged around an axial center of the first output rotating member in a position on an opposite side of the second output rotating member than the high-low switching mechanism, in an axial direction of the first output rotating member, the clutch is pressed on by the pressing member that moves toward the second output rotating member side, the clutch is pressed on by the pressing member when the fork shaft is in a position that places the high-low sleeve in mesh with the high side gear teeth, the clutch is not pressed on by the pressing member when the fork shaft is in a position that places the high-low sleeve in mesh with the low side gear teeth; and 
 the transmitting mechanism includes a connecting mechanism, the connecting mechanism being configured to connect the linear motion member with the fork shaft such that the linear motion member moves between a position where the clutch is pressed on by the pressing member and a position where the clutch is not pressed on by the pressing member, while the fork shaft remains in a position that places the high-low sleeve in mesh with the high side gear teeth. 
 
     
     
       6. The transfer according to  claim 1 , wherein
 the rotating motion member is a threaded shaft member; 
 the linear motion member is a nut member; and 
 the screw mechanism is a ball screw in which the threaded shaft member and the nut member operate via a ball. 
 
     
     
       7. The transfer according to  claim 1 , wherein the clutch is a multiple disc clutch. 
     
     
       8. The transfer according to  claim 1 , wherein the clutch is a single disc clutch.